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Google
Apple
Nvidia
Roblox
Snowflake
Jane Street
HRT
Databricks
Google
Apple
Nvidia
Roblox
Snowflake
Jane Street
HRT
Databricks
Google
Apple
Nvidia
Roblox
Snowflake
Jane Street
HRT
Databricks

Practice what actually gets you the offer.

Top companies don't just filter on LeetCode anymore. 80% of your prep should go toward building real engineering skills: implementation depth, domain knowledge, and systems thinking.

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Real interview problems straight from the source.

We actively interview at top companies (FAANG+, quants) to keep our problems catalog fresh, and stay up to date with the interview meta.

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Learn the minimum set of patterns that covers what top companies actually ask. No repetition, no padding. Just the techniques that transfer directly to interviews.

Complete Search10/12
Recursion6/6
BFS & DFS0/8
Prefix Sums2/7
Stacks & Queues0/2
Getting Started10/11
Maps & Sets6/8
Two Pointers0/2
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Trees0/6
Sorting0/2
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We notice that candidates waste months on the wrong resources & study habits. Most people are also ignorant of resources beyond Leetcode and influencer courses. We compile and organize all the resources out there to help you skip the beginner phase, avoid traps, and land your dream offer.

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LeetCode is just the bar. Strong candidates separate themselves by what they know beyond it: OS internals, concurrency, ML fundamentals, distributed systems. Organized into focused modules.

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Interview problems, sourced from real interviews

Company tags on LeetCode go stale for years. WhiteBox problems come straight from candidates who just interviewed, shared anonymously and curated by our team.

New Submission 3 hours ago
Akuna Capital
Quant Dev Final Round
I got asked this last week and got cooked on this problem ngl. It was implement a lock-free MPSC queue and you had to implement...
Akuna Capital Concurrency 2025 Dec
Anonymous
MPSC Queue – WhiteBox
https://whitebox.ac/problems/mpsc-queue

MPSC Queue

Expert 8 Concurrency Akuna Capital

Implement a lock-free MPSC (multi-producer, single-consumer) queue.

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namespace whitebox
{
template <typename T>
class MpscQueue {
public:
explicit MpscQueue(size_t capacity)
: capacity_(capacity), mask_(capacity - 1),
data_(capacity), seq_(capacity) {
assert((capacity & mask_) == 0 && "capacity must be a power of 2");
for (size_t i = 0; i < capacity_; ++i) {
seq_[i].store(i, std::memory_order_relaxed);
}
head_.store(0, std::memory_order_relaxed);
tail_.store(0, std::memory_order_relaxed);
}
bool push(const T& value) {
size_t pos = head_.load(std::memory_order_relaxed);
while (true) {
size_t tail = tail_.load(std::memory_order_acquire);
if (pos - tail >= capacity_) return false;
if (head_.compare_exchange_weak(
pos, pos + 1,
std::memory_order_acq_rel,
std::memory_order_relaxed)) {
auto& s = seq_[pos & mask_];
while (s.load(std::memory_order_acquire) != pos) {}
data_[pos & mask_] = value;
s.store(pos + 1, std::memory_order_release);
return true;
}
}
}
bool pop(T& out) {
size_t pos = tail_.load(std::memory_order_relaxed);
auto& s = seq_[pos & mask_];
if (s.load(std::memory_order_acquire) != pos + 1) return false;
out = std::move(data_[pos & mask_]);
s.store(pos + capacity_, std::memory_order_release);
tail_.store(pos + 1, std::memory_order_release);
return true;
}
private:
const size_t capacity_;
const size_t mask_;
std::vector<T> data_;
std::vector<std::atomic<size_t>> seq_;
std::atomic<size_t> head_;
std::atomic<size_t> tail_;
};
}
Accepted 20 · 12% acceptance
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Everything in one place.

We built the interview prep platform we wished existed. Here's what sets WhiteBox apart.

WhiteBox
LeetCode / NeetCode
getcracked.io
Codeforces
Interview Transferability Does it reflect what companies actually ask?
Real, current interview problems. Algorithms, systems, implementation.
Algorithmic focus. Transferability varies.
Strong for C++ and quant, narrower scope
Builds fundamentals, steep learning curve
Implementation Problems Real systems, not toy puzzles
Concurrency, ML pipelines, API design, production patterns
Limited, mostly behind paywall
Some
None
Skill Rating How you compare to other candidates
Elo rating with domain strength breakdown
Based on problems solved
Based on problems solved and success rate
Elo rating (contest only)
Tsuki AI Tutor In-editor guidance that teaches, not tells
AI that knows your code, language, and constraints
Leet (premium only)
None
None
AI Mock Interviews Practice speaking under pressure
Voice mock interviews. AI interviewer, rubric grading, debrief reports.
None
None
None
Problem Sourcing How current and relevant the problems are
Community sourced. Exclusive problems continuously added.
Company tags (premium only, often outdated)
Relevant but quant focused niche
Not relevant to interviews
Interview Intel Real questions from recent interviews
Company, date, difficulty. Free for all.
Company tags behind premium, often stale
None
None
Structured Roadmap A clear path to mastery
Skill tree with progress tracking and curated sets per topic
Study plans exist but are rarely updated
Problem list only
No guided path
Gamification Stay motivated long-term
Cosmetics, badges, card frames, leaderboard
Streaks and badges
None
None
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$25/mo, no free tier
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